Fuse construction



Aug. 15, 1950 w. o. SCHULTZ 2,519,078

FUSE CONSTRUCTION Filed Nov. 6, 1943 7 Sheets-Sheet 1 I t g IN VEN TOR.

Mil/AM 0. Jmwrz Aug. 15, 1950 1 w. o. SCHULTZ 2,519,078

FUSE CONSTRUCTION Filed Nov. e, 1945 7 Sheets-Sheet s IN VEN TOR. Mum/u 0, Jaw rz Aug. 15, 1950 w. o. SCHULTZ FUSE CONSTRUCTION Filed Nov. 6, 1943 7 Sheets-Sheet 4 Ill ill! Y 1 INVEN TOR. Mum/11 Q Jmuzrz g- 1950 w. o. SCHULTZ 2,519,078

FUSE CONSTRUCTION Filed Nov. s, 1945 '7 Sheets-Sheet 6 IN V EN TOR.

' Mix/AM 0, Jaw/z I? 6 BY ATTORNEY.

Patented Aug. 1 5, 1950 FUSE CONSTRUCTION William O. Schultz, South Milwaukee, Wis,- as- Signor t Mc raw e i Com an ration of Delaware a corpo- Application November 6, 1943, Serial-No. 509,160

15 Claims. 1

his inventi n rela es t f e onstru ons and while it is particularly applicable to repeating fuse constructions, nevertheless certain phases of the invention are equally applicable to singletypefuse constructions as will appear here inafter.

In fuse devices-as heretofore made it has been the usual practifie to provide transfer switches -which'transfer the'cir'cuit" from one fuse to another fuse-after the first fuse has blown, and to provide time delay'means for delaying the action of the transferswitches. However, in the devices as heretofore made it has been neces-. sary to open the service line at a point in advance of the: fuse constructionwhenever any ad? 'justment of the time delay mechanism was re= quired.

This'invention is designed 'to' overcome the above noted defect and objects of this invention are to provide a fuse construction of the drop: out'type in which time delay means is provided which may beadjusted'withoutopenin the serV-- ice line ahead of the fuse constructiongthe con.- struction of the present invention being such that the time delaymeans'is electrically dead after the fuse tube,-in the caseof a single fuse: tube construction, or the fuse tubes, in the case of a repeating fuse tube construction, have dropped "to open position.

Further objects are to provide a fuse construce tion in whicha simple type'of time delay means has been provided whichdelays' the drop-out motion of the fuse tube and allows the circuit-to be cleared within the fuse tubev prior to the time that the terminal of the fuse tube moves away from the stationaryterminal to thereby avoid arcing at the terminals.

ifn'greaterdetail objects of this invention are to provide a repeating fuse construction of the drop-outtype in which the transfer switches are located at the top of the device to successively connect the stationary upper terminals after the corresponding fuse'tube has moved outwardly to inoperative position, in which time delay means is provided which controls the tube, the tube being arranged to control the transfer switch, in which this time delay means is located adjacent the lower portion of the fuse construction and as stated,- electrically dead Whenfthe fuse tubes have all dropped orbeen moved to inoperative position; and to provide means whereby the time delay meansmaybe adjusted if dc,- sired.

Further objects are o p ov de a dro out use eonstr e oni wh ch t me dela me ns is ero vided for de a n he d op-ou ant cs. of'the fuse tube but in which qu ck 1 a t n "flipp mea ha en pro de hich acts ind nd= ently o the mo ion o 't e fuse t e which one s es hi e he fu e tube remainsin its ODQF-il ive sition to quioklvwit ra a y remai g portion of the fuse link from the fuse tube.

Further bjects are to provide a drop-out fuse cons ruc ion in wh ch heavy conta t s res secur d b tween h upp r stationary te m a and th upper erminal-of th fus tu d in w ch no fl x l l ader ar requ red, a d in which heavy contact pressure is secured between the transfer switch the stationary contacts en? eased by the'transfer switch, and specifically to provide spring means for actuating the transfer switch which isso organized that it exerts its minimum effective pressure when the transfer switch is open and thus reducesfriction at the upper end of the fuse. tube and its maximum efiective pressure when the transfer switch is clos d to securehigh contact pressure for the transfer switch, Further objects are to provide a fuse construc= tion in -Which-a quick acting fiip-out means is provided" which not only withdraws any remain-; ing portion of the fuse link from the fuse tube but releasesthe fuse link and allows it to be thrown or dropped from the fusoxdevice.

Embodiments of the invention are shown in theaccompan-y-ing drawings, in which:

Figure 1 is a side elevationof a repeating fuse construction.

Figure 2 is a front elevation with the first fuse removed and with a partbroken away.

Figure 3 is asectiorial view on the line 3w3of Figure 2.

Figure 4 is a' sectional View Fi ur Figure-5 isa sectional view of the means, such view corresponding to a section-on the line 5+5 of Figure 3.

Figure 6 isa sectional view similar to Figure'i on the line 4e-4 of with fewer of thepa-rts shownin section and showing the fuse tube in the position it occupies in an earlystage of its dropeout motion.

Figure 7 is a view ofthe lower. portion of a fuse tube showing a further form that the invention may take.

Figure 8 is a sectional view on the line 88 oi- Figure 7.

Figure 9 is a View of the lower portion of a fuse tube showing a further form that the invention may take.

Fi ure-1O is a sectional view on the line iii-'10 0. ure 9- Referring tcFigures 1 to 6 showing the first form of the invention, it will be seen that the repeating-fuse construction comprises a plurality of-llppel' terminals indicated generally by thereference characters I, 2 and 3 which are mounted on an insulating bar or member 4. The insulating memberd isprovided with a pair of out; wnrdly pro'l'c i ng bfiri'iersi'located between successive upper terminals. A plurality of lower time delay terminals are provided and are indicated generally by the reference characters 6, .i and 8. One of these lower terminals, for instance the terminal 6, may be provided with a connecting tab or member 9 to which the load is connected. All

of the lower terminals 6, "I and 8 are connected by a conducting bar H). The power line is connected, as indicated in Figure 2, to the first upper terminal I. The upper insulating bar 4 and the lower connectin bar or member iii are carried respectively by means of insulators H and I2 secured to a supporting channel iron or member l3. The member I3 is adapted to be secured to any suitable support.

A plurality of drop-out fuses 14, I5 and 16 are pivotally carried by the lower terminals 6, l and 8 respectively and normally are electrically connected to the uppe terminals l, 2 and 3. These fuse tubes are adapted to successively drop out of position on overload and transfer switches are provided between successive upper terminals.

Time delay meansis provided for delaying the drop-out action of all of the fuse tubes as will be described in detail hereinafter.

4 The upperterminals are each provided with a cam like member ll which is provided with downwardly slanting side faces and Which is formed integral with the corresponding terminal member. A generally U-shaped spring contact arm of relatively heavy material is indicated at 18 and is loosely pivotally held by the terminal member and constitutes a part of the terminal member. The side arms of this U-shaped spring member is tend to move towards each other and grip the cam member I! therebetween. The spring arms coact with the cam member I? and urge the spring arms downwardly. They normally rest against outwardly projecting pins l9 forming a portion of the upper terminal 20 of the corresponding fuse tube. The arms l8 are provided with downwardly depressed portions 2! behind which the pins i9 are normally positioned, the arms therefore acting as yielding latches to hold the corresponding fuse in operative position. The outer ends of the arms l8 are upwardly and outwardly. flaring as indicated at 22 to assist in guiding the fuse into place when it is being rocked to closed position after having been refused. The U-shaped spring arms 18 are positioned beneath an overhanging portion of the corresponding terminal and are loosely held by means of the upwardly turned lip 23 integral with the corresponding terminal. The lip 23 is malleable and is bent upwardly at its end, as shown in Figure 1, after the spring arms it have been placed in position. The spring arms I8, therefore, have free pivotal action with respect to the corresponding upper stationary terminal and have a firm and good electrical contact with the side walls f the cam member I! and also have a firm and good electrical contact with the pins I9 of the upper terminal of the fuse tube, thus providing excellent electrical connection between the upper terminal of the fuse tube and the corresponding upper stationary terminal.

It is to be noted that when a tube drops from operative to inoperative position, the spring arms 18 ride downwardly on the cam member I! and come to. rest when they engage the outwardly projecting portions 24' formed integrally with the cam member H. The details of the construction of the upper contact including the spring arms are more fully described in my Patent No. 2,357,772 of September ,5, 19%, for Cut- Out Construction.

The upper stationary contacts I and 2 differ from the upper stationary contact 3 in that each of the upper stationary contacts I and 2 is provided with a transfer switch mechanism. This transfer switch mechanism comprises a, main 253 is provided with two integral arms, as may be seen from the dotted line illustration in Figure 2, and is provided with a laterally projecting integral extension 21 at the lower end of the lever.

A plungerlike member 28 is provided with a bifurcated rear end which is mounted between thearms of the lever 24 and is pivoted to such arm by means of the pivot pin 29, as shown in Figure 3.- A spring 3!! extends between the pivot pin 29 and a stationary pin 3! carried by the hood 2% and the spring 36 tends to rock the lever 2 1 in a counterclockwise direction. It is resisted, however, as the plunger 28 is held inwardly because the head 32 of the plunger engages the upper terminal of the fuse tube when the fuse tube is in operative position as shown in Figure 3.

The plunger 28 extends through a downward extension of the cam member H and is guided thereby. The head 32 may be made separate from the plunger and may be secured thereto by means of a screw or in any other suitable manner as shown in Figure 2. The transfer switch is pivoted to the lateral extension 21 and is indicated .by the reference characters 33, 34 and shown most clearly in Figure 4. This transfer switch is provided with a long arm 33 and a short arm 35. Each of the arms 33 and 34 is 7 provided with ball like contact portions at their ends which are adapted to engage portions of the stationary upper contacts of successive fuses to thereby transfer the circuit from one upper stationary contact to the next adjacent stationary contact in a manner hereinafter to appear.

A spring 35 extends between lips carried by the arm 33 and the laterally projecting portion 21 of the lever 24. The spring 35 is a, lighter spring than the spring as and normally biases the transfer switch towards open position. The effect of the spring 35 is overcome when the plunger 28 is released and the spring 30 overpowers the action of the spring 35. It is to be noted from reference to Figure 3 that when the fuse tube drops out and the plunger 28 is released, the spring 30 will rock the lever 24 in a counterclockwise direction as viewed in Figure 3 and its effective lever arm will increase as the lever 24 rocks outwardly. Thus an increasing forceis applied by the spring 39 when the spring is free to act and this increasing force is utilized, as will appear hereinafter, to secure a high contact pressure and to exert a greater force on the transfer switch when the switch is in closed position than when the switch is in open position due toth increasing effective lever arm,

It is to be noted from Figure 3 that when the parts are in the position shown, the spring 3i! has its minimum effective lever arm and consequently the force exerted by' the plunger 28 is a minimum. This reduces the friction produced at the upper terminal of the fuse tube between the projecting pins l9 and the depressed portions 2! of the spring arms l8, see Figure 1.

It is to be noted from reference to Figures 2 and 4 that the stationary contacts I and 2 are provided with contact members 36 which form downward extensions of the cam members l1,

sesame-2 ing the lever 24,- see Figure 3,-: to rock outwardly,: .1

the effective-lever arm through-which the spring; 30:; acts .on the lever '24, increasing; as :the lever;;:- 24: IQCkST outwardly; This coutward-grocking of: the. lever: 24 carries its integral'extension 321 out-1.

wardly :and movesthetransfer switch to the po e-l5:

sition=-shown for the left+hand transfer'switch'of 1 Figure 4.? The end 'lOf the short. arm"34 rides on: the contact member 36 and :the end of :the long;- arm- 33 engages the contact member-31 of the 1 upperstationary contact 2. Ahigh-contactpresesure issecurediateach end of thetransfer:switch-:. 33,: (i4: and direct. electrical. connection is -made; between the contact'member 36 ofthe first" upper stationa-ry terminal 1! and-*thecontact member; STof'the second upperstationary terminal 2. The upper stationary terminal :3 is not provided with: any-transfer switch but is provided with the con tact.: rnembe'r-3'l adaptedto be. engaged by'the end 1 ofi the transfer switch of the second upper etationary terminal 2 when thefuse tube. l5; has.;;

rocked 4 downwardly to inoperative position.

It is clear from the description thus far given 1. that no flexible leaders are required between any upper'stationary contact-"and'the spring arms" I 8-; nor is :any. flexible leaderrequired- 'in' association with'the transfer switches: The fuse tubes. are each adapted to havea fuse'link'extending therethrough provided with a flexible leader '38,-

a :fusible section '35 and a button head at its upper end. Any suitablestype :of:-'fuse' link may; however, be employed;

The upper terminals of the :fuse tubes may be 1 provided with any suitable meansfor clamping the button'head in place and for securing good electrical contact therewith: For instance, the-1 5v,

upper terminal of 'eachfuse tube inay be p-ro-s vided' with a pair of levers and 42 which'grip the button head 45 between'them; The lever 4i may beprovidedwith a U'-shaped member 43" through which athuinb screw idis'threaded; the I thumb screw being adapted to bear against the; lever 52, and to thus cla mp the button head in' place: Theengagingsurfa'ce of.'the levers and 22 may be upwardly slantingso-as to facilitate: the outward blowing: of the button head of the fuse link upon very high overloads; Normally thee. head of-the fuse link is'not blown frornthe fuse: tube undenrnoderate or small overloadsbut; under; heavy verloads the fuse: .tube allows venting @atboth ends. This construction-is set .forthin de-.. tailin-my-Patent No; 2,357,772 hereinbefore re.-.' ferred-:to.

Adjacent their lower endszthe fuse tubesieac'hfl carry a rigid, rearwardly-and downwardly eX- tendingarm" whichmay include a :split sleeve portion liCh is held clamped and locked to the lower portion .Ofithe fuse tube :by. means of the bolt ll; such bolt alsofitting 'inxa transverse groove fcrined'in the fuse tube to prevent inad-i vertent turning of the fuse: tube with reference to theclamping sleeve -A t-and arm 55.3, The arm 45=: issin: realitytwo spaced arnish: The supporting? arm structure 1 25 composed of: the two .arm per-- tionsis: pivotedas. indicated at 481;:to:the main-1.

lever re. The;v main lever: is provided with trim-.1- 75 il eZ :flmkfext ndfi ai dzis provided-with a channel laterally projecting grips the leader or end-of nions: zwhichaireremovably received 3within=th.-=-:: hOQki like :.-s1,1pports. 5.1 of the: lower." terminal; memben' Thesmai-n arm; 49 ;is 8.1505 provided with a rear.--

5 wardly. proj ectingc contact portion 52*. which is;

engaged; bypa @relatively; heavywcontacti spring 53:; tQtl'Lllg-SGCHHB firm; electrical .contactbetween the. main arm 49 and the correspondingjlowertstae. tionar terminallwhichlin :the case. of Figure ,3,

pig-indicatedgenerally by: the reference. characterax La. It isg to -bel noted that; the center line of they: trunnion-S259 :is,.,losca ted below and :slightly. 'to :thfiiji: l it of-fthe center-line of thenivotpinv 48.480 that; the; erer;-49-\;.is3.urged downwardly dueito, the;- weightgofxth use:tubeand the parts carried; thereby and ;due to the downward thrustrfrom thespringarms .i 8'; 'whiclrsprin arms actin conesjunction withtheacam member ll.'=.-v The {centerlines ofythfi ztrunnionsfiflxandzof the: pivotzpin 48.

however;- arranged I almost directly. above s thensothat although a .considerab1eidown:-:. Ward-thrustmay be imparted to-the. tube; I 5,1 only: a relatively light turning moment isv imparted to i: the: main lever'49: It'is also-possible; and swith- 1 in thescope of this invention, :to.-,so-arrange the.

Di0t pin;48; Wi-threference to thetrunnions 59?.- that: the center. line, pf the pivotipin is; directly? above thescenter 1ine-of1the trunnionsgiii; andto; rely-;for.- the turning moment of the main'lever 491 heavy contact spring 53;; The main-leverAQ:pivotally carries a fuse; link extracting-and flip-:outlever .Ehvhich is-pro-gs videdwith; a: rounded outer portion. :55-z-about1iwh-ich the-outer. endsof I the, leader- 38' .of the =fl1SB.;:+;

lOWEIi portionwvithin :whichi the, leader-sci the-fuse link: is .positionedv; The; lowerinnergzportion of the-'- fus tube is-slightly rounded n as shown in.- Fig-, ure:.3.-:- The;-;.fuse-1ink gextracting and flip-outrl lever 54 is curved upwardly atdts inner-:enda'andd isnormally-located inclose proximity to the, open lowenend -of;thje.-fuse tube, as shown -.in Figure 3;: It-.-is,;p ivoted to; the main lever by meansaof the pivot.-pin 5B- and-:;is spring urged downwardly: towards fuse link extraetingmotion by; the spring 5.: 51g-10Ilfia 611d :of which bearsrdirectly against: the. fuselinhextractingand flip-out -lever; .54;

Ifjdesiredthe fuse-link extractingand flip-out, lever- 54 may be! provided with a manipulating; thumbpiece-SB; see Figure 1;; A fuse link clampingmember or lever indicated" generally by the-reference character. 5971s also 2 carried a by 1 the pivot 56:, It 'is provided with a shouldered fuse link gripping portion '60 whichthe-:fuse linkbetween: itself :and an overhangingportion B I of the main lever 43? Preferably an outwardly-and upwardly curved shield portion 52 is formedion'the-main levcras shown in Figure 3:

It isrto-be noted 'that. the spring E'P'has its:

wardlya predetermineddistance: When-the ears;-

6310f the-fuse; link extracting lever 54- engage the portion E l-f theqfuse link clamping-lever 5 9;, these two :.1e,vers;. :are -then: interlocked and; the

force or-the spring- 5 1' does notthereafterretaing Ether-fuse;linle clamping:levere59cm: clampingipo-asition; Instead these" two members move as a unit and release the fuse link so that the fuse link will be thrown substantially directly downwardly from the fuse tube, the momentum acquired by the part under the influence of the spring 5'! and gravity being sufficient to carry along the part 59 after the parts 54 and 59 have been locked together.

The main lever 49 is bifurcated and straddles the lower portion of the fuse tube. It is provided with a pair of feet 55 which when the fuse tube has rocked to its lowermost position, engages a portion of the stationary lower contact. The fuse tube transmits the force of the blow due to the fall to the sleeve like portion 46 which is provided with a pair of bearing feet 56, see Figure 6, which engage the main lever 59 at a point substantially directly in line with the feet 65 so that the force of the blow is transmitted from the lower part of the fuse tube substantially directly across the main lever 59 to the lower stationary contact and thus the tendency to bend the main lever 49 is avoided.

The sleeve like portion 43 is provided with an outwardly projecting eyelet like portion 6'! and also provided with a pair of spaced arms 68 so that a switch stick may be inserted between the arms 68 and its knob or head like portion may be engaged within the eyelet portion 61 so that the fuse tube may be lifted into or out of position by means of a switch stick. After a fuse tube has operated in response to overload, it may be lifted out from the stationary hook like members 5! by means of the switch stick and may be refused and repositioned by means of the switch stick. Thereafter the switch stick is caused to engage the eyelet portion or manipulating portion 69 which is integral with the upper terminal 20 of the fuse tube and the fuse tube is rocked back into circuit closed position.

After the fuse link has been extracted, it is to be noted that the lever 59 has rocked about'the pivot pin 58. During refusing the operator rocks the temporary latching member 69' into a position to engage the shoulder 69" of the lever 59 to thus lock the clamping portion 60 in spaced relation to the portion 5|. This facilitates placing the new fuse leader between the clamping member 60 and the cooperating portion 6| during refusing. After the leader has been so placed and the fuse link extracting lever 54 is in the position shown in Figure 3, the temporary latching member 69' is released from the shouldered portion 69 and the clamping member 60 clamps the leader against the member 5 l.

These features are set forth in considerable detail in my Patent No. 2,378,109 of June 12, 1945 for Fuse Construction.

Each of the fuse units is provided with time delay means for delaying the initial portion of the drop-out motion of the fuse tube and causing the fuse tube to remain in operative posit on for a predetermined period after the fuse link has blown. This insures clearing of the circuit within the fuse tube prior to the separation of the'upper terminal of the fuse tube from the upper stationary terminal, and in addition allows the time delay between the opening of the circuit by one fuse and the closing of the circuit through the succeeding fuse so that if the fault is of a transient nature, it will clear itself before the next succeeding fuse is placed in circuit.

It is obvious that although the invention has been described as relating particularly to repeating fuses, the constructionis equally applicable to a single fuse as it insures a time delay so that Jill be seen that the lower stationary contact of each of the fuses is provided with a hood portion it! which houses a time delay bellows mechanism which consists of a bellows H communicating by means of a restricted orifice 1?. with a storage bellows 13. The bellows H and 12 are joined by means of a connecting member '14 which is peripherallygrooved and is supported between a pair of pins '35 carried by the casing 78. The outer end of the bellows H is closed by means of a head 16 which is provided with a pair of pivot pins "if upon which the lower ends of a bifur cated lever IS are pivoted. The lever it is pivoted upon the pivot pin 19 carried by the casing Hi and is provided with an upwardly projecting lip which is adapted to be normally engaged by an adjusting screw 8!, the adjusting screw being provided with a lock nut and being adapted to vary the time delay as will appear hereinafter.

The lever 18 carries a small roller 82 which normally is located below the under side of a laterally projecting lip 83 integral with the sleeve 46 of the fuse tube and having a cam'like lower surface adapted to ride on the roller t2 when the fuse tube executes drop-out motion. Normally the parts are in the position shown in Figure 3 and the bellows H is held in it most extended position by means of the internally located spring 84, see Figure 5. It is clear that if the adjusting screw 8! is projected further to the right as viewed in Figure 3, the roller 82 occupies a lower initial position from that shown in Figure 3 and obviously the length of time that the cam like projecting member 33 engages the roller 82 is shorter and therefore the time delay is lessened.

Assume that all of the fuse tubes are in their operative position. It will be seen that the circuit extends through the first fuse tube is. If an overload occurs, the fuse link is ruptured and any remaining portion thereof is extracted by the fuse link extracting mechanism. This extracting motion is extremely rapid as the flip-out lever or fuse link extracting lever 5e operates independently of any motion of any other part of the apparatus. However, the fuse tube does not immediately rock out of operative position. Instead the cam like member 83 engages the roller 82 and delays the downward motion of the fuse tube. The liquid within the bellows ll flows through the restricted orifice l2, see Figure 5, and consequently delays the motion of the roller 82. This liquid flows into the storage bellows which expands to receive the incoming liquid. The roller 8.2 is thus retarded in its downward motion and consequently the fuse tube is held in contact with the upper resilient spring arms 58. These spring arms follow the fuse tube downwardly a predetermined distance and maintain contact with the upper terminal of the fuse tube.

After the cam like member 83 passes the position shown in Figure 6, it disengages the roller 82. as the cam like member 83 and the lower portion of the fuse tube have an outward and downward rocking motion. Thereafter the fuse tube rocks downwardly to its lowermost position. When the upper terminal 26 of the fuse tube moves away from thehead 32 of the plunger 28, the lever 24 Referring particularly to Figures 3, 5 and 6 it iacrao'zs whenthe tran'sfer switchzis. closed. Consequently 1 the force exerted on the: transfer 'switchiis a maximum when the switch. is closed" and a minimum 'iwhenflthe switchi'is :open. This lessens; the pres- 'sure exerted by thet plunger "28.10n'vthe upper .con-

tactaoi the iuselltubez andsincreases theiicontact pressure oithe transferzswitch:against the coop era'ting stationary contacts'fleand 3'! and insures excellent electrical conneotionbetween successive upper terminals. 'The':time- 'delayfxaffords .ade

qua-te tirne for the circuit to completely clearkit 1. l

self-within 'theiuse tubeprior: to the disengaging "of-- the upper iusei tube-terminal :from the upper st'a'tionary .terminal. In addition tothis it allows "an interval of- 'tirne to Lelapse: before" the second fuse is put into service and if-the -fault isof. an

short duraticnl it is given an opportunity to clear its'elfhefore e; new-fuse is connected into 'the ci-rcuit. If;'on the-other hand, theiault'thasnot "cleared-the second fuse will drop out after apredetermined i-ntervali--and=the third iuse will be placed in service. "Obviouslyif the fault continues, "the third fuse will blow 'and after a'predetermined interval will drop out' 'of ;circuit. '--Anynumber "of fuse units may be employed. In' -theIiorm shownin the drawings 'three 'such units have bee 1 provided.

' In refusing, thelineman lifts the fuse downwardly by means-of a-switch-"stick refuses it I and restores it and thereafter rocks itinto opera- "tive position. If the restored fuse is the first or second fuse in the form shown; it-=wi1l--cause its transfer switch to rock to open posit. n as -the plunger- 2B willbeunoved "inwardly and will consequ'ently rock the lever 24 inwardly to the posi- 'tion shown in Figure 3.

"Time delay mechanism is -provided for each of the fuse units.

3"The time delay feature ie-notonlyapplicable to repeating'fuses but also' is applicable to single fuse "units. 1' In the event-'the' time delay; mechanism is employed in conjunction with a single fuse unit, "it insures the complete clearing of thecircuit vv'ithin the fuse tube -itself prior: to the disengagement ofthe upper iusexter-minal from the upper st'ationary terminal. *It is to be noted-particularly that no fl'eXible Headers or jumpers arerequired. good electrical wco'nta'ct is secured by'meansof' thespring arms i B which engage 'the sides hfthe cam member ll with a heavy contact pressure."Theyflsoengage "the-*pins l 9 ofthe-uppefterminaP 20' ofthe'iuse tube with a firm con-tact pressure and 'bias the sfuse"tube downwardly. This downward pressure may" be relatively heavy andyetvwill not excesssivelystrain the fuse link hut-will producea pull mot exceeding that for which the:fuseulink is'in- "tended.

i In additiomtoE-this the heavy oontact pres- =sure-betWeen 't-he knobs or biall-shapedendsot the 'transfer switclrarms and -the stationary contacts- "starts the rotation oftheflywhecls the operation of' themain lever quently 'delaysxithe" drop-out motion of the' -fitse tube.

provides; anexcellent electrical CODHB'CtiOII 'F'bG- tween successive upper stationary terminals and :avoids thenecessity of the use of-flexible leaders 'for. thetransfer switches.

'The COIlStlllCtiOIl,"fiS stated, issuchithat the effect of the. spring,

.see' Figure 3, is' a'maximurn when the transfer switch is iniclosedpositionv and isa minimum "when the: transfer switch is in open. position.

.It'is to :ben'oted particularly that whenathe fuse tubes havedropped out of service orihave been-moved out of serviceposition, the lowerstationary" contacts :and theLtiine delay mechanisms are electrically dead asthey are connectedztdthe "load line :and' areidisconnected from". the mower line.

Consequently it is possiblef to adjust the time delay mechanism without. any :dange 'ito :the operator. -:Where:time:delaymechanisms are located adjacent the line terminals. of .thelfuse construction, 'itLisFimpossibIe to make any adjustment of the time delay.mechanism'nwithout opening the power.- lineat. a: point 'in advance- 6f the'fuse construction: and thug. taking" that lentire section of the power line out. of service vuntil after the adjustment has been made. 'With 'the "presentinvention'itzis: possible to make this adjustment and leave. the esxdescribed"hereinabove.

Other time 'delay means-could' be employed. "in

power" line in service :the form' of the inventionsv shown in Figures' '7 and 8,1'the'main lever '49.is provided'with segment gears BSTWhichJengage 'pinions=' 86 "rig"id 81. Obviously paddle *wh'eelscoiil'd be employed 'in place of flywheels if-so desired. The flywheels '8 l-i and ithepinions 8 S: are-mounted on a"shaft1'88 which' iscarried 'by the arm fi' lower portion of the' fuse' tube. It -isapparent that when the fuse link ruptured;- the" fiip -out mechanism 'hereinbeforefdescribed operates to withdraw; any'remaining' portion ofthe fuse 'lin'k rocks downwardly-arid 8 I? This delays 49's andconseand that the main lever 49' In the form of the invention shown in Figures -9 and 10, the fuse tube is -providedwith' a sleeve Z 89 rigid therewith. "The sleeve is integral'with a pair of outwardly projecting spaced arms sfl which terminate in downwardly projectingf foot portions 9!. The portions 9! normally rest-upon the'main lever 92 whichis provided with' a-pair of outwardly projecting trunnions 93adapted to be received within the stationary hook-shaped supports 5i, see Figure 3, of the lower terminal.

The main lever 92*consists in realityof'a pair of spaced side portions-joinedby a transverse Web 94.

Figure 9. 'The h'ousingpit will Joe-noted from'F'ig- 'ure' 9, is provided with a downwardly proj ecting -stop portion'lla for a purpose hereinafter to-iappear. The housing 95 is provided with flat shou-lder like facesor portions s5'. These portions normally interlock "with upstanding fingers- 90' integral with the-arms" 99, as shown in Figure Q. The" purpose of this 1 construction'--wil1--appear hereinafter.

The fusetube-is alsoprovided-with aLSIBeVGL' SQ of'the fuse tube. 'pair of inwardly projecting arms Nil whichare rigid therewith and spaced from the lower end This sleeve is integral with a pivoted. by means of the screws Hi! to a pair of auxiliary levers I02 pivoted on the pin Hi3 carried by the housing 95. The screws ill! extend into the head portion I04 of the time delay bellows 35, the storage bellows being indicated by the reference character I06. The intermediate portion I! is carried between a pair of pins H38 passing through the housing. The bellows construction is the same as that disclosed in Figure 5 andhereinbefore described.

' The leader of the fuse link is clamped by means of the thumb nut I09 to the main lever 92. If desired, the lever 92 may be provided with a pair of guiding fingers H0 between which the fuse link extends.

When the fuse link is ruptured, the lever 92 will rock downwardly and act in the manner of a flip-out lever to quickly withdraw any remaining portion of the fuse link. .When the lever 92 rocks downwardly, it will move away from the foot portion 9|. The fuse tube will move downwardly, being urged downwardly by means of the upper stationary contact not'shown but hereinbefore described, and this downward motion will be retarded by means of the time delay bellows mechanism. The members 90' and the portions 95' will remain in sliding engagement with each other for a predetermined interval of time and finally the members 90 will pass from the portions 95' and the fuse tube is then free to rock outwardly at its lower portion due to the col- "lapsing of the toggle mechanism formed by the projecting portions I00 and the levers Hi2. The

upper terminal of the fuse tube will now disengage itself from the upper stationary terminal.

The lip 98 of the housing 95 provides a stop against which the arms I00 of the sleeve 98 normally bear.

in all forms of the invention arestoring spring corresponding to the spring 84, see Figure 5, is provided for the main bellows and in all forms of the invention it is to be understood that the timedelay bellows mechanism is filled with a suitable liquid which will withstand temperature changes and which will be sufficiently fluid under all conditions to pass from the main bellows to'the storage bellows through a restricting orifice.

In all forms of the invention the time delay is so proportioned as to insure clearing of the circuit within the fuse tube prior to the disengagement of the upper terminal of the fuse tube from the upper stationary terminal.

Any form of the invention may be used either as a single fuse structure or as a repeating fuse construction.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. A repeating drop-out fuse construction comprising a plurality of fuse units each including upper and lower terminals, an insulating fuse tube mounted for drop-out motion, and a fuse link normally connecting the upper and lower terminals; transfer switches for connecting successive upper terminals; normally inactive spring actuated means controlled by the fuse tubes for closing the corresponding transfer switch when a fuse tube executes drop-out motion, said spring actuated means being arranged to produce their greatest effect when said transfer switches are in closed position to thereby produce high contact pressure; mechanism for each fuse tube controlled by the fuse link of such fuse tube for normally holding the fuse tube in operative position and releasing the fuse tube for drop-out motion upon rupture of the fuse link; and time delay means adjacent the lower portion of said fuse tubes arranged to hold each fuse tube in operative position for a predetermined interval of time after rupture of the corresponding fuse link.

2. A repeating drop-out fuse construction comprisin a plurality of fuse units each including upper and lower terminals, an insulating fuse tube, and a fuse link within said fuse tube nor,- mally connecting said upper and lower terminals; said fuse tubes being biased for drop-out motion and being normally restrained by the corresponding fuse links; transfer switches adjacent the upper terminals for connecting successive upper terminals; movable switch supporting means supporting said transfer switches, said transfer switches being pivoted on said switch supporting means and arranged for rotary and translatory motion, each switch supporting means being under the control of a fuse tube; and time delay means for delaying the connecting of successive terminals.

3. A repeating drop-out fuse construction comprising a plurality of fuse units each including upper and lower terminals, an insulatin fuse tube, and a fuse link within said fuse tube normally connecting said .upper and lower terminals; said fuse tubes being biased for drop-out motion and being normally restrained by the c0rresponding fuse links; transfer switches adjacent the upper terminals for connecting successive upper terminals; movable switch supporting means supporting said transfer switches, said transfer switches being pivoted on said switch supportin means and arranged for rotary and translatory motion, each switch supporting means being under the control of a fuse tube; and time delay means for delaying the drop-out motion of said fuse tubes.

4. A repeating drop-out fuse construction comprising a plurality of fuse units each including upper and lower terminals, an insulating fuse tube, and a fuse link within said fuse tube normally connecting said upper and lower terminals; said fuse tubes being biased for drop-out motion and being normally restrained by the corresponding fuse links; each of said upper terminals having stationary contacts; transfer switches adjacent the upper terminals for connecting successive upper terminals, each of said transfer switches having contacting portions at each of the ends thereof adapted to engage the stationary contacts of a pair of upper terminals, and movable supporting means for each transfer switch biased towards switch closed position, each transfer switch being pivoted intermediate its ends to the corresponding supporting means and each of said transfer switches being under the control of a fuse tube.

5. A repeating drop-out fuse construction comprising a plurality of fuse units each including upper and lower terminals, an insulating fuse tube, and a fuse link within said fuse tube normally connecting said upper and lower terminals; said fuse tubes being biased for dropout motion and being normally restrained by the corresponding fuse links; each of said upper ternals, an, insulating fuse tube mounted ;:for downward and outward r ck neymo i n, and a-fus link;-within said fuse ;tube nor-mally connecting s d; upper and lower e m na s; said.- fuse tube being biased for dropeout motion and being :nor mally restrained by the correspondingfusejinks; transfer switches adjacent the gupper terminals for, :connecting successive upper'terminals, each ofzsaid'transfer switches being under the control of a; fuse tube and arrangedntoautomatically lose upon rop-ou mo ion of th corr pondin fuse tube; said fuse tubes lhaying project-ing ,portiQIlS; time delay meansfor each fusetube, each time delay means including ;a -1movab le. member normally located below the projecting portion of thecorresponding fuse tube andbellows mech" anism for delaying the ,motion of the-corresponding movable member, said bellows ,mechanism havingarestricted escapeorificaeacn time delay means being connected to. thegcorresponding lower terminal and being electrically dead after the corresponding fuse tube has rocked downwardly and outwardly,

7. A repeatingdrop-out fuso construction comprising a plurality of fuse units each including upper line terminals and lower load terminals, an insulating fuse tube mounted for downward and outward rocking motion, and a fuse link within said fuse tube normallyzconnecting said upperand lower terminals; said fuse tubes being biased for drop -out motion and being normally restrained by the corresponding fuselinks; transfer switches adjacent the upper terminals forv connecting wsuccessive upper terminals, each of said transfer switches being under the control of awfusetubeand arranged to automatically close upon drop-out motionof thecorresponding fuse tube; said fuse tubes havinglprojecting portions; time delay means for: each. fuse tube, each time delay means includinga'movable member normally located below the projecting portion of the corresponding fuse tubelandbellows mechanism for delaying the motion f the movable member, said bellows mechanism havingla-restricted escape orifice; and means for adjusting the initial position of said movable members, each time delay means being connected to the corresponding lower terminal and being electrically dead after the corresponding fuse tube has rocked downwardly and outwardly.

8. A repeating drop-out fuse construction comprising a plurality of fuse units each including upper line terminals and lower load terminals, an insulating fuse tube mounted for downward and outward rocking motion, and a fuse link within said fuse tube normally connecting said upper and lower terminals; said fuse tubes being biased for drop-out motion and being normally restrained by the corresponding fuse links; transfer switches adjacent the upper terminals for connecting successive upper terminals, each of- ;said "transfer switches being K under the control of a fuse tube and arranged to automatically close upon drop-out motionof the corresponding fuseitu-be; slidably related'interlocking means forrnormally. preventing the outward-motion of the lower ends of said fuse tubes and detachable when said; fuse tubes have moveddown-wardly a predetermined distance to permit outward motion of the lower ends of said fuse tubes; and time delay means for delaying the downward motion of said fuse tubes, each time delay means beingfgcon 'looted to thecorresponding lower terminal andbeing electrically dead after the .corresponding fuse, tube has rocked downwardly and outwardly.

9;. A drop-out fuse construction comprising an upper line terminal and a lower load stationary terminal, aninsulating fuse tube normally occupying an operative position and adapted to move to aninoperative positiorii, a fuse link within said fuse tube normally connecting said terminals, supporting mechanism controlled by said fuse link forsupporting said fuse tube in operative positionandadapted to releasesaid use tubefor drop-outmotion-on rupture of d fuse link; said fuse tube having a projecting portion, a movable membeiwadapted to be engaged by said projecting portion upon rupture of fuse link forlcontrolling the drop-out motion of said fuse tube, and time delay bellows mechanism for delaying the action of said movable said time delay bellows mechanism having a restricted escape orifice said time delay bellows, mechanismbeing connected to the c rresponding lower terminal and :being electrically dead after said fuse tube has moved to inoperative posi ion 10; A' dIOD- Out fuse cons .ctlon comprising an upper and a lower statonary terminal; an insulatingfuse tube normally occupying an opera. ti-ve position and adapted to move to an inoperative position, a fuse lin "'it-hin said fuse tube normally -connecting erminals, supporting mechanism controliedby said fuse link for supadapted to release said fuse motion on rupture of tube having a projectn member adapted to be eged by'said projecting portion upon rupture c, 'd fuse link for controllingthe drop-out motion ofsaid fuse tube, time delay bellows mechanism for slaying the action of said movable ll, inber, said time delay bellows mechanism having a restricted escape orifice, and means for adjusting the initial positioQo-fsaidmovable member.

I 11. A dropout fuse construction comprising an upper line terminal and a lower load station: ary terminal, an insulating fuse tube normally occupying an operative position and adapted to move downwardly and outwardly to inoperative position, a fuse link within said fuse tube normally connecting said terminals, supporting mechanism normally supporting said fuse tube in operative position and controlled by said fuse link and releasing said fuse tube for drop-out motion upon rupture of said fuse link, slidably related interlocking means normally holding said fuse tube against outward motion and permitting downward motion of said fuse tube, and re tarding bellows mechanim delaying the downward motion of said fuse tube, said bellows mechanism having a restricted escape orifice, said bellows mechanism being connected to the corre sponding lower terminal and being electrically for drop-out l ink, said fuse portion, a movable dead after said fuse tube has moved to inopera tive position. 7

. 12. A repeating drop-out fuse construction comprising a plurality of fuse units adapted to be successively connected in an electric circuit, each fuse unit including upper and lower terminals, an insulating fuse tube mounted for drop-out motion, and a fuse link normally connecting the upper and lower terminals; transfer switches for successively connecting said fuse units in said circuit, each transfer switch being controlled by a fuse tube; normall inactive spring actuated means controlled by the fuse tubes for closing the corresponding transfer switch when a fuse tube executes drop-out motion, each spring actuated means including a pivoted lever and a spring secured at one end to said lever and fixed at its other end in spaced relation to said lever and arranged to have an increasing effective lever arm as said transfer switch approaches closed position whereby said spring actuated means will produce their greatest effect when said transfer switches are in closed position to thereby produce high contact pressure; mechanism for each fuse tube controlled by the fuse link of such fuse tube for normally holding the fuse tube in operative position and releasing the fuse tube for dropout motion upon rupture of the fuse link; and time delay means for holding said fuse tubes in operative position for a predetermined interval of time after rupture of the corresponding fuse link.

13. A repeating drop-out fuse construction comprising a plurality of fuse units each including upper and lower terminals, an insulating fuse tube mounted for drop-out motion, and a fuse link normally connecting the upper and lower terminals; transfer switches for connecting successive upper terminals; normally inactive spring actuated means controlled by the fuse tubes for closing the corresponding transfer switch when a fuse tube executes drop-out motion, said spring actuated means being arranged to produce their greatest effect when said transfer switches are in closed position to thereby produce high contact pressure; and mechanism for each fuse tube controlled by the fuse link of such fuse tube for normally holding the fuse tube in operative position and releasing the fuse tube for drop-out motion upon rupture of the fuse link.

14. A repeating drop-out fuse construction comprising a plurality of fuse units adapted to be successively connected in an electric circuit, each fuse unit including upper and lower terminals, an insulating fuse tube mounted for drop-out motion, and a fuse link normally connecting the upper and lower terminals; transfer switches for successively connecting said fuse units in said circuit, each transfer switch being controlled by a fuse tube; normally inactive spring actuated means controlled by the fuse tubes for closing the corresponding transfer switch when a fuse tubeeXecutes drop-out motion, said spring actuated means being arranged to produce their greatesteffect when said transfer switches are in closed position to thereby produce high contact pressure; and mechanism for each fuse tube controlled by the fuse link of such fuse tube for normally holding the fuse tube in operative position and releasing the fuse tube for drop-out motion upon rupture Of the fuse link.

15. A repeating drop-out fuse construction comprising a plurality of fus units each including upper and lower terminals, an insulating fuse tube, and a fuse link within said fuse tube normally connecting said upper and lower terminal's; said fuse tubes being biased for dropout motion and being normally restrained by the corresponding fuse links; each of said upper terminals having stationary contacts; transfer switches mounted for rotary and translatory motion adjacent the upper terminals for conporting means towards switch closed position;

' each-of said supporting means being under the control of a fuse tube.

WILLIAM o. SCHULTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,059,796 Johnson Nov. 3, 1936 2,063,466 Schultz et al Dec. 8, 1936 2,081,814 Hermann May 25, 1937 2,109,090 Pittman et a1. Feb. 22, 1938 2,204,320 Schultz June 11, 1940 2,265,765 Schultz et a1 Dec. 9, 1941 2,265,766 Schultz et al Dec. 9, 1941 2,268,899 Ramsey Jan. 6, 1942 2,268,911 Triplett Jan. 6, 1942 2,269,130 Schultz Jan. 6, 1942 2,305,996 Schultz et a1 Dec. 22,1942 2,310,466 Schultz et al Feb. 9, 1943 2,324,114 Schultz et a1 July 13, 1943 2,328,818 Lindell Sept. 7, 1943 2,331,839 Link Oct. 12, 1943 2,423,258 Schultz July 1, 194'? 

